I asked the female bartender that question and she said generally not. She may have thought I was referring to her, or maybe not.
My first concern is that I don't even know if the person is gay. At this point I'm willing to risk a no, getting punched, or maybe even beat up.
My second concern would be impeding their work performance by interrupting them outside of a customer relation. I don't want to take up too much of their time while they're on the clock. I definitely wouldn't want them getting reprimanded or fired because I stopped them from working. That may be something I'll just have to risk if I do, though.
If hitting on a waiter (yours or another) isn't acceptable, how would you go about meeting guys? When is it acceptable it hit on a guy if not at their job? Clubs are already out as I can't hold a conversation when I can't even hear myself. Would you randomly stop some guy at the store, a fellow shopper, and ask them out?